数字校园基于UDK的实现

数字校园是校园信息化建设的重要组成部分,建立虚拟现实的三维校园的通常做法是使用VRML、C++或其它语言。本文在数字校园的三维地图研究中讨论了虚拟现实的几项常用技术,再从整个项目的设计制作流程出发,结合三维游戏引擎大幅提高了操作与执行效率,以实现漫游引擎的主要功能。     

基于动态存储结构的地图贴图算法的改进与实现

游戏地图的算法在整个游戏设计中占有重要地位。通过对游戏地图算法的研究,本文对游戏地图贴图算法中的效率问题进行了分析,提出了改进算法,并在Visual C＋＋的环境下实现。通过改进地图图块的存储方法,将地图图块的句柄和地图图块的索引值等数据以二叉排序树结构的方式存储,使动态树可以随游戏的进度动态地往地图上添加图块,结构灵活,速度快。     

Hilbert packed R树在空中交通管制GIS显示中的研究与应用

现有空中交通管制(ATC)地理信息系统(GIS)重绘时遍历整个地图模型来绘制所有图元,影响了地图显示的速度.针对这一问题,设计了基于Hilbert packed R树的地图绘制算法,首先为每一个图层建立Hilbert packed R树索引,以此为基础每次重绘时采用深度优先遍历的绘制方法重绘地图.试验结果表明,该算法有效地提高了地图显示的速度.     

基于地图的虚拟现实开发技术研究

虚拟实现技术是当前的研究热门,将其与地图数据结合起来,将赋予它更加广泛的应用领域。本文讨论的正晃基于地图的虚拟现实开发技术。     

交通三维视景仿真软件设计方法

在当前的交通仿真研究中，虚拟现实技术的应用是热点之一也是难点之一，矛盾主要在于二者都是硬件资源的消耗大户。在目前的主流PC配置下，传统的设计方法无法给虚拟现实技术以充分的发挥空间。为此，文章提出了基于路段交通统计数据的显示模块设计新方案，并在此基础上通过分割地图多PC处理虚拟城市以及独立出显示模块，在自由交通流基础上对仿真结果二次逼近等手段突破了交通仿真研究中虚拟现实技术的应用在计算机硬件能力和网络传输能力上的瓶颈，并完成了基于Paramics—WTK平台的三维视景仿真软件。真正实现了虚拟城市环境下的交通仿真。     

基于面向对象空间数据库的三维地景可视化研究

该文设计了一个基于面向对象空间数据库的三维地景(terrain)可视化系统,并依据人们对地图的理解角度提出了面向对象的四级数据模型,研究了场景生成技术,开发了底层的面向对象的空间数据库。系统具有良好的通用性和可扩展性,在飞行模拟、实时动态仿真及虚拟现实等领域有较广泛的应用前景。     

改进生成树算法的多机器人在线地图覆盖

研究在线多机器人地图覆盖。在单机器人生成树STC算法基础上做出改进,融入了市场拍卖算法,使机器人团体扩散地生成树,并沿各自生成树完成地图覆盖。通过两种不同环境地图覆盖仿真,结果验证改进后的IMPSTC算法,能够使机器人团队在更少的时间和重复覆盖区域情况下完成在线覆盖地图任务。     

用于地图内容查询的可视化交互界面的设计

可视化交互界面技术是计算机技术的主要组成部分之一，在各个领域中发挥着重要的作用，用于地图内容查询系统的可视化交互界面以高效、灵活和方便的交互手段为系统提供了强有力的支持。文中对用于地图内容查询系统的可视化交互界面具有的功能进行了分析，设计了一种基于语义模型和图像处理技术地图目标查询的交互界面。对界面的总体结构和交互机制进行描述，说明用于描述地图内容的数据结构，并对实现多种功能的操纵方法进行说明.最后给出一个应用实例，说明该界面的效果。     

一种基于三维建图和虚拟现实的人机交互系统

以提高人机共融水平为目的,以救援机器人为背景,提出并实现基于三维建图和虚拟现实(VR)技术的人机交互系统.在该系统中,救援机器人基于多线激光雷达和惯性测量单元(IMU)实时构建环境的三维点云地图,并将建图结果增量式地表示为3D-NDT地图,实时传输至操作台的虚拟现实系统中可视化;同时,操作人员利用虚拟现实系统的交互设备生成机器人的控制指令,控制机器人运动,构成一个完整的人在回路的人机交互系统.该系统在将机器人环境实时在虚拟现实中可视化的基础上,可以给操作人员以极强的沉浸感,有利于操作人员更直接地理解机器人所处环境.此外,该系统作为一种新的人机交互方式,为提高人与机器人的自然交互水平提供了新思路,对促进人机交互技术的发展具有重要意义.     

基于SLAM的虚拟现实六自由度输入系统研究

在虚拟现实(VR)系统中,手控器的三维位姿定位与追踪是至关重要的功能。虽然被动式的六自由度(6DoF)输入方案比较稳定,但是这种系统通常需要额外的硬件,因此比较昂贵,并且其建立和初始化需要额外的空间和时间成本。因此基于视觉惯性即时定位与地图构建(SLAM)的主动式定位,提出一种易于部署且便于携带的六自由度输入系统,作为虚拟现实的手控器。为验证其在三维交互任务中的表现,设计了一组与现有商业手控器的用户对比实验。用户对比实验表明,所提出的主动式六自由度输入系统在虚拟现实交互任务中与现有的商业控制器具有相当的性能。     

地图语言艺术化的本质与目标分析

运用艺术学、心理学等理论与方法分析了地图语言艺术化的本质与目标。认为地图语言艺术化的本质是要使地图语言成为公众易于接受和乐于接受的形式,全面体现人性化设计理念。地图语言艺术化的主要目标是使地图语言精巧化、审美化、形象化、情感化。     

Enhancing the experience of 3D virtual worlds with a cartographic generalization approach

In this work we propose a new approach for fast visualization and exploration of virtual worlds based on the use of cartographic concepts and techniques. Versions of cartographic maps with different levels of details can be created by using a set of operations named cartographic generalization. Cartographic generalization employs twelve operators and domain-specific knowledge, being the contribution of this work their transposition to 3D virtual worlds. The architecture of a system for 3D generalization is proposed and the system is implemented. Differently from traditional cartographic processes, we use artificial intelligence for both selecting the key objects and applying the operators. As a case study, we present the simplification of the historical quarter of Recife (Brazil).     

Real-time map labelling for mobile applications

It is essential to label roads, landmarks, and other important features on maps for mobile applications to help users to understand their location and the environment. This paper aims to examine real-time map labelling methods suitable for the small screen on mobile devices. A slider method with a continuous search space was proposed to sequentially label both line and point features. The method starts with defining a range box for possible locations of the label. Then a search is performed, and the range box is reduced, if there are any cartographic objects that overlap the range box. Finally, the label is placed, at the best possible position in the reduced range box according to normal cartographic preferences, where it does not obscure any cartographic object. We implemented this method in a Java environment using the open source library JTS Topology Suite. A case study showed sound cartographic results of the labelling and acceptable computational efficiency.     

Tabu Search Heuristic for Point-Feature Cartographic Label Placement

The generation of better label placement configurations in maps is a problem that comes up in automated cartographic production. The objective of a good label placement is to display the geographic position of the features with their corresponding label in a clear and harmonious fashion, following accepted cartographic conventions. In this work, we have approached this problem from a combinatorial optimization point of view, and our research consisted of the evaluation of the tabu search (TS) heuristic applied to cartographic label placement. When compared, in real and random test cases, with techniques such as simulated annealing and genetic algorithm (GA), TS has proven to be an efficient choice, with the best performance in quality. We concluded that TS is a recommended method to solve cartographic label placement problem of point features, due to its simplicity, practicality, efficiency and good performance along with its ability to generate quality solutions in acceptable computational time.     

Heuristics for cartographic label placement problems

The cartographic label placement problem is an important task in automated cartography and Geographical Information Systems. Positioning the texts requires that overlap among texts should be avoided, that cartographic conventions and preference should be obeyed. This paper examines the point-feature cartographic label placement problem (PFCLP) as an optimization problem. We formulate the PFCLP considering the minimization of existing overlaps and labeling of all points on a map. This objective improves legibility when all points must be placed even if overlaps are inevitable. A new mathematical formulation of binary integer linear programming that allows labeling of all points is presented, followed by some Lagrangean relaxation heuristics. The computational tests considered instances proposed in the literature up to 1000 points, and the relaxations provided good lower and upper bounds.     

Multiple representations for cartographic objects in a multi-scale tree—An intelligent graphical zoom

In Geographic Information Systems, a function to draw cartographic sketches quickly and in arbitrary scales is needed. This calls for cartographic generalization, a notoriously difficult problem. Efforts to achieve automatic cartographic generalization were successful for specific aspects, but no complete solution is known, nor are there any expected within the immediate future. In practical applications, a base map is stored and its scale is changed. Without major distortions, only changes to twice or half the original scale are feasible by simple numeric scale change. Everything beyond this requires adaptation of symbols, selection of objects, placements of labels, etc.

Extending ideas of hierarchies or pyramids, where representations of the same objects at different scales are stored, a multi-scale, hierarchial spatial model is proposed. Objects with increasing detail are stored in levels and can be used to compose a map at a particular scale. Applied to the particular problem of cartographic mapping, this results in a multi-scale cartographic tree. The same concept can be used equally well for other applications, which require rendering of objects at different levels of detail.

The structure of the multi-scale tree is explained. It is based on a trade-off between storage and computation, replacing all steps which are difficult to automate by essentially redundant storage. The dominant operation is ‘zoom,’ which moves towards a more detailed level, intelligently replacing the current graphical representation with the more detailed one, appropriate for the selected new scale. Methods to select objects for rendering are based on the principle of equal information density. Principles of possible implementations are presented.     

Virtual reality: The non-temporal cartographic animation and the urban (large) scale projects

The evolution of digital technology has placed cartography in a dialog on questions concerning the new abilities, its form and prospective. The cartographic presentation in three dimensions has as a basic feature: the simulation with the natural ability of understanding the space.One of the problems that arose in virtual environments refers to the use of scale in relation to the analysis and the study of space. This relation of geographic analysis and cartographic tools is strictly defined in traditional cartography, but in the virtual cartographic environment the rules of optical understanding and measurement of space are defined by an arbitrary free moving of the sight, that prescribes the natural vision and therefore the perception of the specific space.In close relation with the cartographic motion is the cartographic visualization of the time and the relevant techniques: splitting of time, creation of motion frames, timing, rapidity, motion pattern, etc.The specific work describes, through specific examples that focus mainly on urban areas, methodological and technical approaches concerning the concept of time and scale problems in virtual cartography, but mainly contributes in the ongoing scientific dialogue concerning the theoretical documentation of Virtual Cartography.Finally,we regard Computational Intelligence as a comprehensive and effective algorithmic platform for mechanisms of Virtual Reality.     

A cartographic approach to visualizing conference abstracts

A cartographic approach to mapping nongeographic information helps to manage graphic complexity in visualizations. It aids domain comprehension by forcing us to use the same cognitive skills we use when viewing geographic maps. The author presents a distinctly cartographic approach to mapping nongeographic information. Focusing on the text content of a set of conference abstracts, we can derive 2D visualizations of information spaces that address complexity and automation